Hearing system

ABSTRACT

The present disclosure relates to a hearing system. The hearing system comprises an implantable device configured to be implanted under the skin of a wearer and an external device configured to be positioned at an ear of the wearer. The external device comprises a transmit system configured to generate a wireless signal for being transmitted to the implantable device.

FIELD OF THE DISCLOSURE

The present disclosure relates to a hearing system including animplantable device and an external device. The implantable device isconfigured to be implanted beneath the skin of a user and receivewireless signals from the external device.

BACKGROUND

When a person suffers from a hearing loss where is not possible totransform sound signals into signals in an audible frequency range usinga hearing instrument, a cochlear implant may be used for electricalstimulation to the auditory nerve in the inner ear. Both children andadults with a severe to profound hearing loss, who cannot be helped withordinary hearing instruments, may be helped with cochlear implants.Cochlear Implants (CI) are today a very successful treatment for peoplewith profound hearing losses. CI's operates by stimulating the auditorynerve fibres electrically. The cochlea itself is a conical helicalchamber of bone including the fluid-filled scala tympani and scalavestibuli separated by the basilar membrane on which sound inducedmechanical waves travel. The base of the cochlea, nearest the round andoval windows, is relatively stiff and responsive to high frequencies;the apex of the cochlea is tuned to receive lower frequencies, tonotopicorganisation, when functioning, hair cells respond to the motion offluid to generate electrical signals. Generally, the electrode array isimplanted into the scala tympani.

A Cochlear Implant typically includes i) an external part for picking upand processing sound from the environment, and for determining sequencesof pulses for stimulation of the electrodes in dependence on the currentinput sound, ii) a (typically wireless, e.g. inductive) communicationlink for simultaneously transmitting information about the stimulationsequences and for transferring energy to iii) an implanted base partallowing the stimulation to be generated and applied to a number ofelectrodes, which are implantable in different locations of the cochleaallowing a stimulation of different frequencies of the audible range.Such systems are e.g. described in U.S. Pat. No. 4,207,441 and in U.S.Pat. No. 4,532,930.

The CI electrode may comprise multi-electrode array e.g. in the form ofa carrier comprising a multitude of electrodes adapted for being locatedin the cochlea in proximity of an auditory nerve of the user. Thecarrier is preferably made of a flexible material to allow properpositioning of the electrodes in the cochlea such that the electrodesmay be inserted in cochlea of a recipient. Preferably, the individualelectrodes are spatially distributed along the length of the carrier toprovide a corresponding spatial distribution along the cochlear nerve incochlea when the carrier is inserted in cochlea.

If the user have residual hearing in one ear, a cochlear implant at oneear may be combined with a hearing device providing an acoustic signalat the ear with residual hearing may be provided, e.g. as disclosed inUS 2010/030012.

One way of establishing a hearing system having an cochlear implant isto use an implantable base part and two electrodes, each electrodeconfigured to be implanted into a respective cochlear, wherein the basepart is to be implanted near one ear, and the first electrode is to beimplanted into the proximal cochlear while the other electrode isimplanted into the distal cochlear. In this configuration, only onemajor part is to be implanted. In order to provide a binaural signal tothe user, one external device having a microphone system and a transmitdevice is positioned at the ear of the distal cochlear, and anotherexternal device having a microphone system and a receive device ispositioned at the ear of the proximal cochlear may be provided. The twoexternal devices may then be connected via a wire transferring signalsbetween the two devices, primarily from the distal device to theproximal device. The device at the proximal cochlear then processes thereceived signal before transferring it to the implanted base unit. Thissystem is cumbersome, and users have complained about the wiredconnection.

Hence, an improved hearing system would be advantageous, and inparticular, a more efficient hearing system with wireless connectionbetween an implanted device and an external device and between theexternal device and an additional second external device would beadvantageous.

In a system providing acoustic signal to the ear canals of a user,synchronization between a first auditory prosthesis and a secondauditory prosthesis of a bilateral auditory prosthesis system isdiscussed in US 2012/224705. In this system, a primary wirelesscommunications channel, usable for synchronizing the first and secondprostheses, may be disabled to, for example, conserve power.

It is an object of the present disclosure to provide at least analternative to the prior art.

SUMMARY

Thus, the above-described object and several other objects are intendedto be obtained in a first aspect by providing a hearing systemcomprising an implantable device and an external device. The implantabledevice may be configured to be implanted under the skin of a wearer andthe implantable device may including two electrode devices eachconfigured to stimulate a respective cochlear of the wearer. Thestimulation of the respective cochlear is of cause when the implantabledevice in an implanted state. The implantable device may be configuredto receive a wireless signal and convert the wireless signal to astimulation signal to be applied via the electrodes to a respectivecochlear. During use of the implantable device, an external deviceconfigured to be positioned at an ear of the wearer may be used. Theexternal device may comprise a microphone system for receiving acousticsignals and converting the acoustic signals to an electrical signalrepresenting the acoustic signals, a processor including an encoder toencode the electrical signal to an encoded signal, where the encoder isconfigured to divide the electrical signal into a plurality of frequencybands and determine an energy level for each band. The external devicemay be composed of several sub-devices or sub-systems each performingone or more tasks. The external device may comprise more functionsand/or components. The external device may further comprise a transmitsystem configured to generate the wireless signal based on the encodedsignal and configured for transmitting the wireless signal to theimplantable device.

Further, a second aspect provides a method for operating a hearingsystem comprising an implantable device and an external deviceconfigured to transmit an encoded signal to the implantable device, theexternal device comprising a microphone system and a processor system.The method may comprise a step of receiving at the microphone systemacoustic signals. The method may comprise a step of converting theacoustic signals to electrical signals via the microphone system, wherethe conversion includes dividing the signal into a plurality of bands.The method may comprise a step of determining for each of the pluralityof bands an energy level. The method may comprise a step of generating awireless signal based on the plurality of energy bands. The method maycomprise a step of transmitting the wireless signal from the externaldevice to the implantable device.

This second aspect of the disclosure is particularly, but notexclusively, advantageous in that it may be accomplished by a computerprogram product enabling a hearing system according to the first aspectto carry out the operations of the hearing system of the first aspect ofthe disclosure when down- or uploaded into the hearing system. Such acomputer program product may be provided on any kind of computerreadable medium, or through a network.

The individual features of each aspect may each be combined with any orall features of the other aspects. These and other aspects, featuresand/or advantages will be apparent from and elucidated with reference tothe embodiments described hereinafter.

BRIEF DESCRIPTION OF THE FIGURES

The apparatus/method is described below in more detail with regard tothe accompanying figures. The figures illustrates exemplaryimplementations and is not to be construed as being limiting to otherpossible embodiments falling within the scope of the attached claim set.

The figures are schematic and simplified for clarity, and they just showdetails to improve the understanding of the claims, while other detailsare left out. Throughout, the same reference numerals are used foridentical or corresponding parts.

FIG. 1 schematically illustrates a hearing system having an implantabledevice and two external devices,

FIG. 2 schematically illustrates a hearing system having an implantabledevice with two electrodes, an external device and a remote, externaldevice,

FIG. 3 schematically illustrates steps of a method,

FIG. 4 schematically illustrates relationship between two blocks ofenergy levels, and

FIG. 5 is a schematic illustration of relationship between differentnumbers of bits.

Generally, a “hearing system” refers to a system comprising one or twohearing devices to be placed at respective ears of the wearer, and a“binaural hearing system” refers to a system comprising two hearingdevices where the devices are adapted to cooperatively provide audiblesignals to both of the wearer's ears. A binaural cochlear hearing systemincludes a system where an electrode is present in each cochlear,whereby both cochlear are stimulated to provide the user with a binauralhearing sensation.

The hearing system or binaural hearing system may further includeauxiliary device(s) that communicates with at least one hearing device,the auxiliary device affecting the operation of the hearing devicesand/or benefiting from the functioning of the hearing devices. A wiredor wireless communication link between the at least one hearing deviceand the auxiliary device is established that allows for exchanginginformation (e.g. control and status signals, possibly audio signals)between the at least one hearing device and the auxiliary device. Suchauxiliary devices may include at least one of remote controls, remotemicrophones, audio gateway devices, mobile phones, public-addresssystems, car audio systems or music players or a combination thereof.The audio gateway is adapted to receive a multitude of audio signalssuch as from an entertainment device like a TV or a music player, atelephone apparatus like a mobile telephone or a computer, a PC. Theaudio gateway is further adapted to select and/or combine an appropriateone of the received audio signals (or combination of signals) fortransmission to the at least one hearing device. The remote control isadapted to control functionality and operation of the at least onehearing devices. The function of the remote control may be implementedin a SmartPhone or other electronic device, the SmartPhone/electronicdevice possibly executing an application that controls functionality ofthe at least one hearing device.

FIG. 1 schematically illustrates a top-down view of a wearer having animplanted device 12 at the left-side of the head 10. The implanteddevice 12 is connected to two electrodes 14 and 16. The electrode 14 ispositioned in the proximate cochlea relative to the implanted device 12,while the electrode 16 is positioned in the distal cochlea relative tothe implanted device 12.

A first external device 18 is positioned the left ear, and a secondexternal device 22 is positioned the right ear. Having two externaldevice allows, among other, the provision of a binaural signalrepresenting sound recorded at the correct ear, without requiring anyestimation of head-related-transfer function or the like processing. Thesignal from either or both external devices may be based on one or moremicrophones at respective external device. The external device 18includes an antenna 20, and the external device 22 includes an antenna24. The antennae 20 and 24 are configured so that they facilitatecommunication at least from the external device 22 to the externaldevice 18. Communication may also be performed from the external device18 to the external device 22 as well. A wireless link between theexternal device 22 and the external device 18 is energy intensive, andenergy storage in the form of batteries in compact devices such ashearing instruments is limited. Further to this, the bandwidth in thewireless link between the external device and either the other externaldevice and/or the implantable device is limited. Therefore, there is aneed for reducing the amount of energy consumed in the transmissionprocess.

Further, an even further external device, such as a mobile phone orremote microphone, may communicate with one of the external devices 18and/or 22 for providing a signal to be presented to the user. This couldbe via a telecoil system or the like.

The external device 18 and 22 is here of a behind-the-ear type, but maytake other forms, such as in-the-ear or partly in-the-ear.

The antenna devices, 20 and 24, are included in the external device 18and 20, here shown as extending from the housing of the external device18, 20. The antenna device 20, 24 is configured to transmit a wirelesssignal between the two external devices. One way of doing this is by useof an inductive link, which utilizes low loss in the link between twodevices at frequencies around 4 MHz. Alternatively, higher carrierfrequencies may be used, e.g. in the ISM band, such as at 2.4 GHz or at5 GHz or in the range 433 MHz-434 MHz, or at the 868-MHz band, or anyother suitable frequency range.

The implantable device 12 comprises two main parts, namely a first partto be positioned between the skull and the skin of the wearer. Thisfirst part comprises an implant antenna for receiving a wireless signalfrom external device. The second part of the implantable device 12 isconfigured to be embedded into the each of the cochlea so that thecochlea is directly stimulated by signals representing sound. This isrepresented by the electrodes 14 and 16.

The external device 18 comprises an input transducer. The inputtransducer is here a direction sensitive microphone system, withadaptable directionality. Alternatively, the input transducer may be afixed direction microphone system. Further alternatively, the inputtransducer may be an omnidirectional microphone, where each of theexternal devices 18 and 22 comprises such an omnidirectional microphone,and the two omnidirectional microphone signals are processed to form thesignal presented to the user.

The external device 18 comprises a processor for generating a signal tobe transmitted to the implantable device 12. The signal is representedby the dashed line between the external device 18 and the implantabledevice 12.

In a particular version of the external device 22, available filterbanks and level estimators are used to compute 12 energy levels with16-bit resolution. The number 12 is here chosen as it corresponds to thenumber of stimulation points in the electrode positioned in the cochlea.The 12 energy levels thus represents 192 bits of information. Thisinformation is then transmitted as data every 2 ms to the externaldevice 18, yielding a transfer rate of 96 kb/second. If the availablefilter banks do not match the needed frequency bands for the speechprocessor in the first part, an FFT filter bank can be implemented tocalculate the levels. In general, the number of energy levels may behigher or lower than 12. In general, the number of bits used torepresent each energy level may be higher or lower than 16 bits, such as32 bits, or 8 bits. Generally, the number of bits may be in the range of2 to 70 bits, such as 8 bits, such as 12 bits, such as 16 bits, such as18 bits, such as 22 bits, such as 32 bits, such as 64 bits. Generally,the signal may be transmitted repeatedly, such as with a time intervalof 1 ms to 50 ms, such as every 1 ms to 20 ms, such as every 5 ms to 10ms, such as every 1 ms, such as every 2 ms, such as every 5 ms.

This constrains the amount of data transmitted from the external device22 to the external device 18, thereby reducing the power requirements,relative to transferring full audio between the two external devices.

In a further attempt to reduce power consumption for the transmission, asubset of the 12 energy levels may be chosen. Such a subset could be 8energy levels, further reducing the amount of data to 128 bit pertransfer. Even further reductions are possible if additional coding ofthe subset is performed. The dynamic range of sound is approximately 100dB, but the dynamic range on the electrode is far less, in usualelectrodes around 10-20 dB. So, less resolution is actually needed,i.e., fewer bits. If, instead of the 12 energy levels, transmit thecharge/energy level with which we wish to stimulate the 12 (or 8)electrodes, this would even further reduce the data requirements. Thiscould bring the bit usage down from e.g. 16 bit to 8 bit pr. level.

From the external device 18, a charging signal may be sent to theimplantable device 12, which includes an energy storage module. Thecharging may be performed as background charging or precharging, so thatenergy is transferred to the implantable device 12 before anyinformation is sent.

If energy is supplied from the external device 18 to the implantabledevice 12, the implantable device may receive the signal to be presentedto the user from either the external device 18 or the external device22, but in addition to this, even from a further external device, suchas a mobile phone.

FIG. 2 schematically illustrates a hearing system similar to that ofFIG. 1, but with a remote, external device 22′ configured to transmit awireless microphone signal via the antenna 24 to an antenna 26 of theimplantable device 12.

FIG. 3 is a schematic illustration of steps of a method for operating ahearing system such as a hearing system described in connection withFIG. 1 and FIG. 2.

The method comprises a step of receiving at the microphone systemacoustic signals. In considering the method, this step may be replacedor be in addition, a step of receiving an external signal from a remotedevice, such as an external microphone worn by a person.

The method comprises a step of converting the acoustic signals toelectrical signals via the microphone system. In the method, theconversion includes dividing the signal into a plurality of bands, anddetermining for each of the plurality of bands an energy level. Themethod comprises a step of generating a wireless signal based on theplurality of energy bands; the wireless signal is configured to betransmitted via the antenna system of the external device to the antennasystem of the implantable device.

The method may be extended to include several more steps, and may berepeated so that the communication between the devices is perceived as acontinuous streaming of sound to the ear of the user. This could includetransmitting a package representing the plurality of bands each 2 ms orso.

FIG. 4 schematically illustrates reducing the total information levelfrom 12 energy levels to 8 energy levels, thereby reducing the amount ofdata needed to be transferred via the wireless link. The eight energylevels are packaged, or encoded, into the wireless signal to betransmitted to the implanted device. The encoding may include areduction of the amount of data representing the information.

FIG. 5 schematically illustrates reducing the total information levelfrom 16 bits pr. energy level to 8 bits pr. energy levels, therebyreducing the amount of data needed to be transferred via the wirelesslink. The eight bits pr. levels are packaged, or encoded, into thewireless signal to be transmitted to the implanted device. The number ofbits may be chosen as discussed above.

Combinations of the above embodiments and many other embodiments will beapparent to those of skill in the art upon reading and understanding theabove description.

In one instance, the present disclosure relates to a hearing systemcomprising an implantable device configured to be implanted under theskin of a wearer and the implantable device including two electrodedevices each configured to stimulate a respective cochlear of thewearer, the implantable device configured to receiving a wireless signaland convert the wireless signal to a stimulation signal to be appliedvia the electrodes to a respective cochlear, an external deviceconfigured to be positioned at an ear of the wearer, the external devicecomprising: a microphone system for receiving acoustic signals andconverting the acoustic signals to an electrical signal representing theacoustic signals, a processor including an encoder to encode theelectrical signal to an encoded signal, where the encoder is configuredto divide the electrical signal into a plurality of frequency bands anddetermine an energy level for each band, and the external device furthercomprising a transmit system configured to generate the wireless signalbased on the encoded signal and configured for transmitting the wirelesssignal to the implantable device.

The apparatus and/or method steps as set out in the claims may beimplemented by means of hardware, software, firmware or any combinationof these. Some of the features could also be implemented as softwarerunning on one or more data processors and/or digital signal processors.

The individual elements of any of the disclosed embodiments may bephysically, functionally and logically implemented in any suitable waysuch as in a single unit, in a plurality of units or as part of separatefunctional units. It is intended that the structural features of thedevices described above, in the detailed description and in the claimsmay be combined with steps of the method, when appropriately substitutedby a corresponding process. Embodiments of the method have the sameadvantages as the corresponding systems.

Although the present disclosure discusses specific embodiments, theclaims should not be construed as being in any way limited to thepresented examples. Although specific embodiments have been illustratedand described herein, it will be appreciated by those of ordinary skillin the art, that any arrangement which is calculated to achieve the samepurpose may be substituted for the specific embodiments shown. The scopeof protection is defined by the accompanying claim set. In the contextof the claims, the terms “comprising” or “comprises” do not excludeother possible elements or steps. Also, the mentioning of referencessuch as “a” or “an” etc. should not be construed as excluding aplurality. The use of reference signs in the claims with respect toelements indicated in the figures shall also not be construed aslimiting the scope of the claims. Furthermore, individual featuresmentioned in different claims, may possibly be advantageously combined,and the mentioning of these features in different claims does notexclude that a combination of features is not possible and advantageous.

1. A hearing system comprising: an implantable device configured to beimplanted under the skin of a wearer and the implantable deviceincluding two electrode devices each configured to stimulate arespective cochlea of the wearer, the implantable device configured toreceiving a wireless signal and convert the wireless signal to astimulation signal to be applied via the electrodes to a respectivecochlea, an external device configured to be positioned at an ear of thewearer, the external device comprising: a microphone system forreceiving acoustic signals and converting the acoustic signals to anelectrical signal representing the acoustic signals, a processorincluding an encoder to encode the electrical signal to an encodedsignal, where the encoder is configured to divide the electrical signalinto a plurality of frequency bands and determine an energy level foreach band, the external device further comprising a transmit systemconfigured to generate the wireless signal based on the encoded signaland configured for transmitting the wireless signal to the implantabledevice, a second external device comprising a microphone system forreceiving acoustic signals and converting the acoustic signals to asecond electrical signal representing the acoustic signal, the secondexternal device configured to transmit the second electrical signal tothe external device, and the external device generating the wirelesssignal based on the electrical signal and the second electrical signal.2. The hearing system according to claim 1, wherein the wirelesscomprises an inductive link and/or a radio frequency link.
 3. Thehearing system according to claim 1, wherein the encoded signal consistof the energy level for each band.
 4. The hearing system according toclaim 1, wherein the plurality of frequency bands is in the range of 20to 4, such as 18 to 7, such as 15 to 11, such as
 12. 5. The hearingsystem according to claim 1, wherein each energy level is represented bya plurality of bits in the range of 2 to 70 bits, such as 8 bits, suchas 12 bits, such as 16 bits, such as 18 bits, such as 22 bits, such as32 bits, such as 64 bits.
 6. The hearing system according to claim 1,wherein the encoding of the electrical signal includes a reduction forreducing the amount of information for at least one level.
 7. Thehearing system according to claim 1, wherein filter banks levelestimator in the external device constitutes the processor.
 8. Thehearing system according to claim 1, wherein the external device is ahearing aid, and/or the implantable device is or incorporates a cochlearimplant.
 9. A method for operating a hearing system comprising animplantable device and an external device configured to transmit anencoded signal to the implantable device, the external device comprisinga microphone system and a processor system, the method comprising:receiving at the microphone system acoustic signals, converting theacoustic signals to electrical signals via the microphone system, wherethe conversion includes dividing the signal into a plurality of bands,determining for each of the plurality of bands an energy level andgenerating a wireless signal based on the plurality of energy bands,transmitting the wireless signal from the external device to theimplantable device.
 10. The method according to claim 9, wherein thewireless signal is transmitted every 1 ms to 50 ms, such as every 1 msto 20 ms, such as every 5 ms to 10 ms, such as every 1 ms, such as every2 ms, such as every 5 ms.
 11. The method according to claim 9, furthercomprising: receiving at the implantable device the wireless signal,converting the wireless signal to a signal to be presented to the user,which signal the user perceives as sound, wherein the signal ispresented via an electrode configured to be positioned in the cochlear.12. The method according to claim 9, wherein the generation of thewireless signal further comprises creating a compressed signal havingreduced data for at least one energy level.
 13. The hearing systemaccording to claim 2, wherein the encoded signal consist of the energylevel for each band.
 14. The hearing system according to claim 2,wherein the plurality of frequency bands is in the range of 20 to 4,such as 18 to 7, such as 15 to 11, such as
 12. 15. The hearing systemaccording to claim 3, wherein the plurality of frequency bands is in therange of 20 to 4, such as 18 to 7, such as 15 to 11, such as
 12. 16. Thehearing system according to claim 2, wherein each energy level isrepresented by a plurality of bits in the range of 2 to 70 bits, such as8 bits, such as 12 bits, such as 16 bits, such as 18 bits, such as 22bits, such as 32 bits, such as 64 bits.
 17. The hearing system accordingto claim 3, wherein each energy level is represented by a plurality ofbits in the range of 2 to 70 bits, such as 8 bits, such as 12 bits, suchas 16 bits, such as 18 bits, such as 22 bits, such as 32 bits, such as64 bits.
 18. The hearing system according to claim 4, wherein eachenergy level is represented by a plurality of bits in the range of 2 to70 bits, such as 8 bits, such as 12 bits, such as 16 bits, such as 18bits, such as 22 bits, such as 32 bits, such as 64 bits.
 19. The hearingsystem according to claim 2, wherein the encoding of the electricalsignal includes a reduction for reducing the amount of information forat least one level.
 20. The hearing system according to claim 3, whereinthe encoding of the electrical signal includes a reduction for reducingthe amount of information for at least one level.